Linking Error when use Class Template in VC6 [modified] - C / C++ / MFC Discussion Boards

Zac Howland15-Sep-06 9:08

15-Sep-06 9:08

Consider using OpenFile or ofstream to open the file instead of fopen. Also, if you use ofstream, you can use the string class instead of CString. It has similar functions to CString, and you also gain the ability to use some of the more complex STL algorithms if you need them.

I'm assuming this is an actual file you are opening (that is, it isn't a serial port) so if you wanted to, you could easily load the entire file into memory to parse it.

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week

Zac

Displaying continous values

Pratheep Kenny14-Sep-06 22:56

Pratheep Kenny

14-Sep-06 22:56

Hi all,

I have designed a MFC based Dialog application. I have a parent dialog and a corresponding child dialog.

My requirement is this. My parent dialog has a edit box. Which should display value form 0 to n without stopping although the child window is opened or closed.

Just like a clock it should be incrementing the value by itself. Which function do u suppose can be used to achieve this?

I tried WM_TIMER but to no avail. It increments once and then stops.

Please some one tell me as to which function or handle can accomplish this.

Thanks and Regards in Advance
Kenny

Re: Displaying continous values

Rinu_Raj14-Sep-06 23:01

Rinu_Raj

14-Sep-06 23:01

Use a thread function to implement the edit box updation.

Threadproc()
{
m_edit = 1; // edit box member variable
while( 1 )
{
m_edit++
UpdateData(FALSE);
sleep( 10 )
if( m_edit == n ) // return if n is reached
{
return;
}
}

Rinu Raj

Problem with fonts in DC ?

Vinod Sankaranarayanan14-Sep-06 22:49

Vinod Sankaranarayanan

14-Sep-06 22:49

Hi all,

I want to draw some diagrams (rectangles ...etc) and put text in to it..

I have used TextOut() function to write the text...

But I want to reduce the font size ....

Now it takes current font settings of Device Context...

How do I make it ?

Thanks in advance....

vinsankar

Re: Problem with fonts in DC ?

kk.tvm14-Sep-06 22:52

kk.tvm

14-Sep-06 22:52

Hi
Use CreateFont to set font size.

Attach font object to dc using SelectObject

Re: Problem with fonts in DC ?

Steve S14-Sep-06 22:52

Steve S

14-Sep-06 22:52

Are you using the original (default) font in the DC, or have you selected your own in? I'm guessing the former, since if you were selecting them in, you'd just create a smaller one.

Steve S
Developer for hire

Re: Problem with fonts in DC ?

Hamid_RT15-Sep-06 7:26

Hamid_RT

15-Sep-06 7:26

You can use of CreateFontand SelectObject but in the end use CFont::DeleteObject and also you can use of CreateFontIndirect

WhiteSky

Linking Error when use Class Template in VC6 [modified]

Andy Rama14-Sep-06 20:42

Andy Rama

14-Sep-06 20:42

I create an 'Win32 Console Application' "Program01" in VC6 as follows,

//Program01.cpp File<br />
#include "stdafx.h"    #include "Class.h"<br />
int main(int argc, char* argv[]){<br />
	Class<int> a;<br />
	int b = a.GetValue(1729);<br />
	printf("\n\t");<br />
	return 0;<br />
}<br />
<br />
//Class.cpp File<br />
#include "stdafx.h"   #include "Class.h"<br />
template <class T><br />
Class<T>::Class(){<br />
}<br />
template <class T><br />
Class<T>::~Class(){<br />
}<br />
template <class T><br />
int Class<T>::GetValue(int value){<br />
	return value;<br />
}<br />
<br />
//Class.h File<br />
template <class T> class Class{<br />
public:<br />
	Class();<br />
	virtual ~Class();<br />
	int GetValue(int value);<br />
};

It shows Linking error for the member functions of class. But when I remove template from Class the program runs well; even when I write all code (Class with template) in single "Program01.cpp" File then also it runs well.
Then what might be the problem in the above code?

-- modified at 4:03 Friday 15th September, 2006

Re: Linking Error when use Class Template in VC6 [modified]

Mr.Brainley14-Sep-06 21:48

Mr.Brainley

14-Sep-06 21:48

This article should awnser you question :

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccelng/htm/tions_35.asp[^]

(pay special attention to the second scentence)

-- modified at 3:53 Friday 15th September, 2006

Re: Linking Error when use Class Template in VC6

Nibu babu thomas14-Sep-06 21:56

Nibu babu thomas

14-Sep-06 21:56

Aniket Salunkhe wrote:
It shows Linking error for the member functions of class. But when I remove template from Class the program runs well; even when I write all code (Class with template) in single "Program01.cpp" File then also it runs well.
Then what might be the problem in the above code?

Template classes should be defined and declared in .h files so that the compiler can generate code for these classes when an instantiation is required.

Because templates are compiled when required, this forces a restriction for multi-file projects: the implementation (definition) of a template class or function must be in the same file as its declaration. That means that we cannot separate the interface in a separate header file, and that we must include both interface and implementation in any file that uses the templates.

Remove definitions from .cpp file to .h file.

These days compilers do allow you to forward declare template types, but some compilers don't yet support them.

// In AClass.h
template < class T >
class AClass
{
    int ATemplateFunction( T aObj );
};
 
// Don't define this function in AClass.cpp but in AClass.h
template< class T >
int AClass< T >::ATemplateFunction( T aObj )
{
   // Have fun
   return 1;
}

Nibu thomas
A Developer

Programming tips[^] My site[^]

Re: Linking Error when use Class Template in VC6

Andy Rama14-Sep-06 22:09

Andy Rama

14-Sep-06 22:09

Nibu babu thomas wrote:
Template classes should be defined and declared in .h files

But I am creating Library ('Wind32 Static Library') using that code, so i can't write implementation of class in .h file.
So what should i do?

Re: Linking Error when use Class Template in VC6

Nibu babu thomas14-Sep-06 22:19

Nibu babu thomas

14-Sep-06 22:19

Aniket Salunkhe wrote:
But I am creating Library ('Wind32 Static Library') using that code, so i can't write implementation of class in .h file.
So what should i do?

Look at what Microsoft has done for their template classes. They do have plenty of them. For eg: CArray, CPtrArray etc.

Nibu thomas
A Developer

Programming tips[^] My site[^]

Re: Linking Error when use Class Template in VC6

Andy Rama14-Sep-06 22:44

Andy Rama

14-Sep-06 22:44

Where should I search for that?

Re: Linking Error when use Class Template in VC6

Nibu babu thomas14-Sep-06 22:46

Nibu babu thomas

14-Sep-06 22:46

Aniket Salunkhe wrote:
Where should I search for that?

AfxTempl.h

Nibu thomas
A Developer

Programming tips[^] My site[^]

How to dynamically change the toolbar tip in MFC?

ziyoo14-Sep-06 20:41

ziyoo

14-Sep-06 20:41

I am doing a MFC project and want to change the tip on toolbar item.
I found some samples on Dialog to do that in codeproject, but none on MainFrame'stoolbar.
Can you help me?

Re: How to dynamically change the toolbar tip in MFC?

ziyoo15-Sep-06 15:30

ziyoo

15-Sep-06 15:30

nobody can help me?

images problem

radhika2814-Sep-06 20:08

radhika28

14-Sep-06 20:08

Hi,
MY application consits of a button and a tree control.If i press the button, windows explorer files and folders will be displayed in the tree control with images.Now my problem is,if i press the button for the second time the images are not appearing in the tree control.How can i eliminate this problem.

Thanks in advance,
Radhika.

Re: images problem

_AnsHUMAN_ 14-Sep-06 20:21

_AnsHUMAN_

14-Sep-06 20:21

radhika28 wrote:
MY application consits of a button and a tree control

What is the type of application?

radhika28 wrote:
if i press the button for the second time the images are not appearing in the tree control.How can i eliminate this problem

Can you post some source code showing how are you going with the creation of the tree control etc....

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: images problem

radhika2814-Sep-06 20:24

radhika28

14-Sep-06 20:24

void CApplication::OnButton1()
{
// TODO: Add your control notification handler code here

TCHAR szWorkDir[MAX_PATH];
if ( m_tree.m_hWnd )
{
if ( m_tree.SubclassDlgItem( IDC_TREE1, this ) )
{
m_tree.DisplayTree( NULL /*Display all*/, TRUE /* TRUE = Display Files*/ );

_getcwd( szWorkDir, 256 );
// set the Path to the current Work-Directory
m_tree.SetSelPath( szWorkDir );
}
}

}

Re: images problem

ThatsAlok14-Sep-06 20:43

ThatsAlok

14-Sep-06 20:43

radhika28 wrote:

TCHAR szWorkDir[MAX_PATH];
if ( m_tree.m_hWnd )
{
if ( m_tree.SubclassDlgItem( IDC_TREE1, this ) )
{
m_tree.DisplayTree( NULL /*Display all*/, TRUE /* TRUE = Display Files*/ );

_getcwd( szWorkDir, 256 );
// set the Path to the current Work-Directory
m_tree.SetSelPath( szWorkDir );
}

you have to check out for some flag !

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You

reading .pst file

neha.agarwal2714-Sep-06 19:01

neha.agarwal27

14-Sep-06 19:01

i just want to read .pst file made by oulook ....
i have tried reading it by using ReadString function .its reading file but the strings r in some code format i just wanted to read 'em in some understandable manner...can anybody plsss give me some tips on how to use .pst file ???Is .pst file use any kind of data structure for storing our emails etc..........

Re: reading .pst file

Christian Graus14-Sep-06 19:14

Christian Graus

14-Sep-06 19:14

pst files us a variant on the Jet database engine. You need to research the file structure and impliment the code to read it if you want to work with them. You really didn't expect it to be a bunch of plain text, did you ?

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

Re: reading .pst file

neha.agarwal2714-Sep-06 19:46

neha.agarwal27

14-Sep-06 19:46

actually i want to recover my deleted files from the outlook.So i m not getting from where to start with??So if u can plssss guide me thru...it'll be of g8t help

Re: reading .pst file

Christian Graus14-Sep-06 20:06

Christian Graus

14-Sep-06 20:06

LOL - I can tell you from personal experience ( outlook died for me earlier this week ) the web is full of people willing to sell you a program that will recover your PST. The sample versions all show you your mail but do not recover it, but I found ones as cheap as $50, which worked really quite well.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

Re: reading .pst file

neha.agarwal2714-Sep-06 20:20

neha.agarwal27

14-Sep-06 20:20

thanku for ur suggestion
if u knw it or u can rather tell me how to read a pst file or in what file format does it contains its content or anythig related to a pst file
it'll be helpfull
thanxs

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.